This invention relates to orthopedic cushions in general, and more specifically to orthopedic wheelchair or other chair or seat cushions.
A well-recognized problem for individuals who are forced to spend extended time seated in wheelchairs or other chairs or seats is the risk of incurring tissue damage, and ultimately the development of decubitus ulcers, at those points on the body that are subject to constant pressure. Decubitus ulcers expose an individual to the risks of infection and irreversible tissue damage, and in any case are difficult to treat. For wheelchair-bound persons, such ulcers typically develop over the bony prominences exposed to pressure while the person is seated, such as the ischia (bony prominences of the buttocks) and the trochanter. Another problem for such individuals is a lack of stability accompanied by a sense of physical insecurity while seated in a wheelchair, and particularly while being moved about in a wheelchair.
There are known to the art, wheelchair cushions that attempt to address these problems by reducing pressure on restricted areas of tissue over bony prominences and redistributing pressure more uniformly over a larger surface area of the buttocks and back of the thighs. Such cushions may include cushions having shaped foam bases and with a cushioning layer on the base. However, a continuing problem for the cushion user is a sense of discomfort, particularly in the trochanter region, due to a transition between the cushioning layer and the base. The transition typically feels like a bump or ridge beneath the upper thighs and, while it does not usually cause tissue damage, is a constant source of discomfort and annoyance to the user. A need therefore exists for a wheelchair or other seat or chair cushion that adequately relieves pressure on pressure points in the regions of the ischia and trochanter, provides the user a sense of stability and security, while at the same time reduces or eliminates the discomfort and annoyance associated with the transition between components of the base.